A microprocessor typically requires an external clock to operate. This clock can be sourced by a reference oscillator that may have a higher frequency that is divided down to a lower frequency for use by the microprocessor or other circuitry requiring a clock.
To reduce manufacturing costs, different models of an electronic device can share the same printed circuit board with only certain components being changed. The different components may require different clock frequencies for proper operation. The different models may also require the clock in different parts of the circuit. These changes would require changing the reference oscillator clock circuit and the board layout each time a different clock is needed. There is a resulting need for an apparatus that automatically senses the clock and directs a modified clock output to the appropriate location depending on the clock's frequency and source.